Sun: hero or villain?

The most interesting chapter from Survival of the Sickest, at least from my perspective, was Chapter III "The Cholesterol Also Rises" because it addressed the grim reality, that what we cling onto for our survival is also contributing to our demise. Prime example, the sun. Without the sun nothing around us would be possible because we have it to thank for our food and air supply. On the flip side, the sun can also cause drought, which often limits the food supply, and deadly skin cancer. I appreciated this combative chapter so much, because there is constantly debate over what promotes health, what chips away at it, what lengthens life and what shortens it. What one person thinks is okay, another person says it should be avoided. I think that judging from our past reads, the stress caused by such worry might be more damaging than the product itself. Now, I am not talking about something like smoking, which I can find no benefit to, but if someone enjoys drinking a diet soda in moderation, then they should do it without worrying about something like cancer that seems to be caused by everything these days. Sticking with the same example, if soda is labeled as a taboo thing in someone's diet, then more likely or not it will become something obsessive and tempting, when it really is something trivial. I think that living by the rule of moderation will keep people happier and more prepared for a long, healthy life.